Question

AB crystallises in a body centred cubic lattice with edge length' a' equal to 387 pm The distance between two oppositely charged ions in the lattice is:

Options

• 335 pm

• 250 pm

• 200 pm

• 300 pm

Answer 1

335 pm

Explanation:

For bcc lattice

`2(r^+ + r^-) = sqrt(3)a`

`(r^+ + r) = (sqrt(3)a)/2`

= `(sqrt(3) xx 87  "pm")/2`

= 335 pm